Electric lamp unit



March 8, 1938. H, A, DOUGLAS 2,110,133

ELECTRIC LAMP UNIT Filed March 2, 1934 Hmgaf A...'Dou.q\.Ae

1 MQ/WMZI Patented Mar. 8, I

PATENT OFFICE ELECTRIC LAMP UNIT Harry A. Douglas, Bronson, Mich assignor to 7 Kingston Products Corporation, a corporation of Indiana Application March 2,

7 Claims.

I My invention relates to electric lamp units, and particularly to electric lamp units comprising an incandescent electric lamp mounted in a reflector, as in an automobile headlight, and the principal 5 object of my inventionis to provide a new and improved unit of this type. In the drawing accompanying this specification, and forming a part of this application, I have shown, for purposes of illustration, one form which my inventionmay assume; in this drawing:

Figure 1 is a longitudinal sectional view of the unit, showing the lamp in elevation,

Figure 2 is a section on the line 2-2 of Figure 1, illustrating particularly the means for securing the lamp in position in the reflector,

Figure 3 is asection on the line 33 of Figure 1, illustrating particularly the connection of the socket unit to the reflector, while Figure 4'is a view in perspective, illustrating 20 additionally in this respect.

The herein disclosed embodiment of my invention comprises a lamp of the two-filament type, having a first filament l4 mounted between a common post |5 and a first selective post It, 25 and positioned in focus, for so-called bright light, and a second filament ll, mounted between the common post l5 and a second selective post |8, and positioned above the focal point, for so-called dim light. The three posts I5 and I6 and I8 are supported in the usual glass body |9, mounted in the lamp base 20, to which is secured the usual bulb 2|, and the common post I5 is grounded to the exterior shell 22 of the lamp base 20, while the selective posts l6 and I8 are secured respectivelyto the contacts 23 and 24, carried by and projecting from the rear face of the lamp base 20. Secured to the lamp base outer shell 22 is the tubular-portion 25 of a positioning ring 26 which comprises also an outwardly extending flange 21 provided with threebayonet slots 53, spaced about the periphery of the lamp base 20, and provided also, on its rear face, intermediate the slots 53, with three positioning projections 28.

Receiving the lamp l is a reflector I 2, comprising a body 29, which may be of parabolic form; and which is provided at its rear with a central aperture 32 adapted to receive the lamp base and the tubular portion of the positioning ring 26.. Surrounding the central aperture 32, at points spaced about the central aperture32, the reflector i2 is provided with three arcuate depressions each containing a bayonet slot 51, and intermediate the slots 51 are surfaces 3| 5 lying in a single plane perpendicular to the axis 1934, Serial No. 713,715

of the unit and adapted to be engaged by the positioning ring projections 28.

Receiving the rear of the lamp base 20 is a socket unit I3 comprising a cylindrical shell 33 provided at its forward end with an integral outwardly extending annular flange 34 which carries three pins 35comprising shanks 50 provided at their forward ends with enlarged heads 49. The rear ends of the shanks 50 are mounted in rearwardly extending bosses 36 struck from the flange 34, and are secured in position, in the bosses 36, by cross pins 31 traversing the bosses 36 and the shanks 50.

Surrounding each pin 35 is a sleeve having a substantially cylindrical body 4| provided at its forward end with an enlarged head 6|. Each sleeve body 4| is provided on opposite sides, at 42, with recesses there reducing the body to a width equal only to the diameter of the pin shank 50. Surrounding the sleeve bodies 4| are compression springs 52, bearing at their rear ends against the socket flange 34 and at their front ends, through washers 44, against the rear surface of the reflector l2, and acting to bias rearwardly the entire socket unit l3, including the pins 35.

If desired, the washers 44 may be constructed as a single annular disc.

The shell 33 is provided at its rear end with three rearwardly extending integral fingers 38 outwardly convexed to form recesses 39 in which is supported an insulating base 43 substantially closing the rear end of the shell 33.

Slidably mounted in the insulating base 43 are two terminal rods 45, which are connected to conductors 46 leading to the control switch, as is well known in the art, and which are provided at their forward ends with heads 41, adapted to contact the terminals 24 and 23 of the lamp base 20, and pressed into firm engagement with the lamp base terminals 24 and 23 by springs 48 en;

circling the terminal rods and compressed between the insulating base 43 and the terminal heads 41.

Each of the positioning ring bayonet slots 53 comprises an entrance 54 adapted to receive a pin head 49, a seat 55 adapted to closely receive a pin shank 50, and a connecting portion 56, connecting the entrance 54 to the seat 55. Each of the reflector flange bayonet slots 51 comprises an entrance 58 adapted to receive a sleeve head 6|,

a seat 59 adapted to closely receive a sleeve body 4|, and a connecting portion 60, connecting the entrance 5,8 to the seat 59, and adapted to receive conveniently assembled with the shell 33 by positioning it in the internal recess 39 before the ends of the fingers 38 have been inturned, or may be sprung into position afterward, as may be desired. l5

reflector 12 by inserting the sleeve heads 6| through the entrances 58 of the reflector bayonet slots 51, continuing the movement against the action of the springs 62, until the reduced portions 42 of the sleeves 40 are alined with the connecting portions 60 of the reflector slots 51, and then rotating the socket unit. l3 relative to the reflector l2,'until the sleeve bodies 4| seat in the seats 59 of the bayonet slots .51, to releasably hold the socket unit 13 assembled with the reflector I2.

To assemble a lamp ll in a reflector 12, the lamp II is inserted, with the entrances 54 of the bayonet slots 53 registering with the heads 49 of the pins 35, and then the lamp is rotated, to bring the pin shanks 5|] into the seats 55 of the bayonet slots 33, with the pin heads 49 overlying the adjacent walls of the lamp positioning flange '21, whereupon the springs 62, acting through the socket shell 33 and the pins 35, urge the projections 28 of the positioning ring flange,

21 into tight engagement with the reflector surfaces 3|. Concurrently, the springs 44B hold the socket contacts 41 in firm engagement with the lamp base contacts 24 and 23.

To assure that any lamp II will be accurately positioned in any reflector 12, each reflector I2 is made accurately to gauge, entirely uniform for all practical purposes, and each lamp is placed in 5 a standard reflector, while its positioning ring 26 is still free, and accurately positioned, with .the projections 28 of the positioning ring flange 21 in flrm engagement with the part of the standard reflector corresponding to the reflector surfaces 3|, and the positioning ring 25 is then secured in fixed position on the lamp base 20, while the parts are so held.

By the use of three projections 28, spaced about the periphery of the lamp base 20, the lamp will beheld firmly positioned, against any tilting, and by forming the bayonet connections other than equally spaced, the construction will be suchthat the lamp can be inserted'in only the one proper position.

skilled in the art that the herein disclosed embodiment of my invention provides a new and im- -proved lamp assembly, accurately positioning the lamp, and readily and convenientlyconstructed, and accordingly, accomplishes at least the'principal object of my invention. 0n the other hand,

The entire socket unit 13 is assembled'with the From the foregoing it will be apparent to those I claim:

1. In combination: an 'lncandescent electric lamp, having a'bas'e; a mounting for said lamp; said base having a lateral extension adapted to abut said mounting; pressing means for pressing said lateral extension against said-mounting; said pressing means and said mounting being so constructed and arranged that they are detachably connectable by bayonet connection; said bayonet connection comprising a bayonet slot in said mounting having a reduced channel between its entrance and seat, and a reduced portion, on said pressing means, constructed and arranged to traverse said'channel, but normally out of alinement with the general plane of said mounting at said channel.

2. In combination: an incandescent electric lamp, having a base; a mounting for said lamp; said base having a lateral extension adapted to abut said mounting; pressing means for pressing said lateral extension against said mounting; said pressing means and said mounting being so constructed and arranged that they are detachably connectable by bayonet connection; and said bayonet connection comprising a bayonet slot in said mounting, and portions of said pressing means, said portions extending through'said slot and being so constructed and arranged that they are relatively movable.

3. In combination: an incandescent electric lamp, having a base; a mounting for said lamp; said base having a lateral extension adapted to abut said mounting at a plurality of points spaced about the periphery of said base said mounting ing said lateral extension against said mounting;

said pressing means and said mounting being so constructed and arranged that-they are detachably connectable by bayonet connection; said bayonet connection comprising a bayonet slot in said mounting having. a reduced channel between its entrance and seat, and a reduced portion on said pressing means, constructed and arranged to traverse said channel, but normally out of alinement with the general plane of said channel; and said pressing means and said lateral extension being so constructed and arranged that they are detachably connectable by bayonet connection.

5. In combination: an incandescent electric lamp, having abase; a mounting for said lamp;

said base having a lateral extension adapted to abut said mounting; pressing means for ,pressing said lateral extension against said mounting; said pressing means and said mounting being so constructed and arranged that they are detachably connectable by bayonet connection; said bayonet connection comprising a bayonet slot in said mounting, and portions of said pressing means, said portions extending through said .slot and being so constructed and arranged that they are relatively movable; and said pressing means and said lateral extension being so constructed and arranged that they are detachably connectable by bayonet connection. A

6. In combination: an incandescent electric lamp, having a base; a mounting for said lamp;

said base having a lateral extension adapted-to lamp, having a base; a mounting for said lamp;

abut said mounting; pressing means for press- Said base having a lateral extension adapted to lug said lateral extension against said mounting; abut said mounting; pressing means for presssaid pressing means and said mounting being so ing said lateral extension against said mounting; 5 constructed and arranged that they are detachsaid pressing means and said mounting being so 5,

said mounting, and portions of said pressing bayonet connection comprising a bayonet slot in means, said slot having areduced channel besaid mounting, and portions of said pressing l0 tween its entrance and seat, said portions extendmeans, said portions extending through said slot I ing through said slot and being so constructed 7 and being, so constructed and arranged that they structed and arrangedtotraverse said channel. said mounting and said lateral extension. 15 7. In combination: an incandescent electric HARRY A. DOUGLAS." 15 

